Performance tweaks for AbstractFile, no review.

1 files changed, 29 insertions, 25 deletions

diff --git a/src/compiler/scala/tools/nsc/io/AbstractFile.scala b/src/compiler/scala/tools/nsc/io/AbstractFile.scala
index 059ca9bd9e..4b196877a3 100644
--- a/src/compiler/scala/tools/nsc/io/AbstractFile.scala
+++ b/src/compiler/scala/tools/nsc/io/AbstractFile.scala
@@ -10,7 +10,7 @@ package io
 import java.io.{ FileOutputStream, IOException, InputStream, OutputStream, BufferedOutputStream }
 import java.net.URL
 import PartialFunction._
-
+import java.io.File.{ separatorChar => separator }
 import scala.collection.mutable.ArrayBuffer
 
 /**
@@ -84,7 +84,6 @@ object AbstractFile {
  * </p>
  */
 abstract class AbstractFile extends AnyRef with Iterable[AbstractFile] {
-
   /** Returns the name of this abstract file. */
   def name: String
 
@@ -137,6 +136,8 @@ abstract class AbstractFile extends AnyRef with Iterable[AbstractFile] {
   /** size of this file if it is a concrete file. */
   def sizeOption: Option[Int] = None
 
+  def toURL: URL = if (file == null) null else file.toURI.toURL
+
   /** Returns contents of file (if applicable) in a Char array.
    *  warning: use <code>Global.getSourceFile()</code> to use the proper
    *  encoding when converting to the char array.
@@ -186,43 +187,47 @@ abstract class AbstractFile extends AnyRef with Iterable[AbstractFile] {
    *  @return          ...
    */
   def lookupPath(path: String, directory: Boolean): AbstractFile = {
-    lookup((f, p, dir) => f.lookupName(p, dir), path, directory)
+    lookupPathInternal(path, directory, false)
   }
 
   /** Return an abstract file that does not check that `path' denotes
    *  an existing file.
    */
   def lookupPathUnchecked(path: String, directory: Boolean): AbstractFile = {
-    lookup((f, p, dir) => f.lookupNameUnchecked(p, dir), path, directory)
+    lookupPathInternal(path, directory, true)
   }
 
-  private def lookup(getFile: (AbstractFile, String, Boolean) => AbstractFile,
-                     path0: String,
-                     directory: Boolean): AbstractFile = {
-    val separator = JFile.separatorChar
+  private def lookupPathInternal(path0: String, directory: Boolean, unchecked: Boolean): AbstractFile = {
     // trim trailing '/'s
-    val path: String = if (path0.last == separator) path0 dropRight 1 else path0
-    val length = path.length()
-    assert(length > 0 && !(path.last == separator), path)
-    var file = this
-    var start = 0
-    while (true) {
+    val path = (
+      if (path0.charAt(path0.length - 1) != separator) path0
+      else path0.substring(0, path0.length - 1)
+    )
+    def loop(file: AbstractFile, start: Int): AbstractFile = {
       val index = path.indexOf(separator, start)
-      assert(index < 0 || start < index)
-      val name = path.substring(start, if (index < 0) length else index)
-      file = getFile(file, name, if (index < 0) directory else true)
-      if ((file eq null) || index < 0) return file
-      start = index + 1
+      if (index < 0) {
+        if (unchecked) file.lookupNameUnchecked(path, directory)
+        else file.lookupName(path, directory)
+      }
+      else {
+        val name = path.substring(start, index)
+        val next = (
+          if (unchecked) file.lookupNameUnchecked(name, true)
+          else file.lookupName(name, true)
+        )
+        if (next == null) null
+        else loop(next, index + 1)
+      }
     }
-    file
+    loop(this, 0)
   }
 
-  private def fileOrSubdirectoryNamed(name: String, isDir: Boolean): AbstractFile = {
-    val lookup = lookupName(name, isDir)
+  private def fileOrSubdirectoryNamed(name: String, directory: Boolean): AbstractFile = {
+    val lookup = lookupName(name, directory)
     if (lookup != null) lookup
     else {
       val jfile = new JFile(file, name)
-      if (isDir) jfile.mkdirs() else jfile.createNewFile()
+      if (directory) jfile.mkdirs() else jfile.createNewFile()
       new PlainFile(jfile)
     }
   }
@@ -249,6 +254,5 @@ abstract class AbstractFile extends AnyRef with Iterable[AbstractFile] {
   protected def unsupported(msg: String): Nothing = throw new UnsupportedOperationException(msg)
 
   /** Returns the path of this abstract file. */
-  override def toString() = path
-
+  override def toString = path
 }